Method and apparatus for resource allocation and bandwidth part inactivity timer handling for vehicle-to-everything communication

ABSTRACT

A communication method and system for converging a fifth generation (5G) communication system for supporting higher data rates beyond a fourth generation (4G) system with a technology for Internet of things (IoT) are provided. The communication method and system may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method by a terminal for acquiring a system information (SI) message is provided. The method includes receiving, from a base station, a plurality of synchronization signal blocks (SSBs), determining at least one physical downlink control channel (PDCCH) monitoring occasion associated with each of the plurality of SSBs in an SI window, and monitoring at least one PDCCH monitoring occasion associated with at least one of the plurality of SSBs to acquire the SI message.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119(e) to U.S. Provisional application Ser. No. 62/732,775, filed on Sep.18, 2018, in the U.S. Patent and Trademark Office, the disclosure ofwhich is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates generally to a mobile communication system, andmore particularly, to a system and a method of resource allocation andbandwidth part (BWP) inactivity timer handling for vehicle-to-everything(V2X) communication.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of fourth generation (4G) communication systems, efforts havebeen made to develop an improved fifth generation (5G) or pre-5Gcommunication system, also referred to as a ‘beyond 4G network’, a ‘postlong term evolution (LTE) system’, or a new radio (NR) system. The 5Gwireless communication system is considered to be implemented not onlyin lower frequency bands, but also in higher frequency (mmWave) bands,such as 10 GHz to 100 GHz bands, so as to achieve higher data rates.

To mitigate propagation loss of the radio waves and increase thetransmission distance, beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,analog beam forming, and large scale antenna techniques are beingconsidered in the design of the 5G wireless communication system. Inaddition, in 5G communication systems, development for system networkimprovement is underway based on advanced small cells, cloud radioaccess networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul, moving network, cooperativecommunication, coordinated multi-points (CoMP), and reception-endinterference cancellation, for example. In the 5G system, frequency andquadrature amplitude modulation (FQAM), which is a combination of hybridfrequency shift keying (FSK) and quadrature amplitude modulation (QAM),and sliding window superposition coding (SWSC) as an advanced codingmodulation (ACM), filter bank multi-carrier (FBMC), non-orthogonalmultiple access (NOMA), and sparse code multiple access (SCMA) as anadvanced access technology, have been also developed.

In a similar regard, the Internet is now evolving to the Internet ofthings (IoT) where distributed entities, such as things, exchange andprocess information without human intervention. The Internet ofeverything (IoE), which is a combination of IoT technology and big dataprocessing technology through connection with a cloud server, has alsoemerged. As technology elements, such as “sensing technology,”“wired/wireless communication and network infrastructure,” “serviceinterface technology,” and “security technology” have been demanded forIoT implementation, a sensor network, a machine-to-machine (M2M)communication, machine-type communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. In thiscase, IoT may be applied to a variety of fields including a smart home,smart building, smart city, smart car or connected cars, smart grid,health care, smart appliances, and advanced medical services throughconvergence and combination between existing information technology (IT)and various industrial applications.

Consistent with this, efforts have been made to apply 5G communicationsystems to IoT networks. For example, technologies such as a sensornetwork, MTC, and M2M communication may be implemented by beamforming,MIMO, and array antennas. Application of a cloud RAN as theabove-described big data processing technology may also be considered asconvergence between the 5G technology and the IoT technology.

Recently, several broadband wireless technologies have been developed tomeet the growing number of broadband subscribers and to provide theseand other additional and improved applications and services. The secondgeneration (2G) wireless communication system was developed to providevoice services while ensuring the mobility of users. The thirdgeneration (3G) wireless communication system supports not only thevoice service, but also data service. The 4G wireless communicationsystem was developed to provide high-speed data service, but suffersfrom lack of resources to meet the growing demand for high-speed dataservices. Therefore, the 5G wireless communication system is beingdeveloped to meet the growing demand of various services with diverserequirements, such as high-speed data services, and to supportultra-reliability and low latency applications.

In addition, although the 5G wireless communication system is expectedto address different use cases having divergent requirements in terms ofdata rate, latency, reliability, and mobility, it is expected that thedesign of the air-interface of the 5G wireless communication systemwould be flexible enough to serve user equipments (UEs) having divergentcapabilities depending on the use case and market segment in which theUE caters service to the end customer.

Example use cases the 5G wireless communication system is expected toaddress include enhanced mobile broadband (eMBB), massive MTC (m-MTC),and ultra-reliable low latency communication (URLL). The eMBBrequirements, such as high Gbps data rate, low latency, and highmobility, address the market segment representing the conventionalwireless broadband subscribers needing Internet connectivity everywhereand full-time. The m-MTC requirements, such as very high connectiondensity, infrequent data transmission, long battery life, and lowmobility, address the market segment representing the IoT/IoEenvisioning connectivity of billions of devices. The URLL requirements,such as very low latency, very high reliability and variable mobility,address the market segment representing the industrial automationapplication, and vehicle-to-vehicle/vehicle-to-infrastructurecommunication that is foreseen as one of the enablers for autonomouscars.

Vehicular communication services, represented by vehicle-to-everything(V2X) services, can include vehicle-to-vehicle (V2V),vehicle-to-infrastructure (V2I), vehicle-to-network (V2N) andvehicle-to-pedestrian (V2P) types. V2X services can be provided by PC5interface and/or Uu interface. Support of V2X services via PC5 interfaceis provided by V2X sidelink communication, which is a mode ofcommunication whereby UEs can communicate with each other directly overthe PC5 interface, and is supported when the UE is served by nextgeneration radio access network (NG-RAN) and when the UE is outside ofNG-RAN coverage. Only the UEs authorized to be used for V2X services canperform V2X sidelink communication.

The UE supporting V2X sidelink communication can operate in two modesfor resource allocation:

(1) Scheduled resource allocation, in which:

-   -   The UE needs to be radio resource control connected        (RRC_CONNECTED) in order to transmit data, and    -   The UE requests transmission resources from the next generation        node B (gNB), which schedules transmission resources for        transmission of sidelink control information and data.

(2) UE autonomous resource selection, in which:

-   -   The UE unilaterally selects resources from resource pools and        performs transport format selection to transmit sidelink control        information and data, and    -   The UE performs sensing for (re)selection of sidelink resources.        Based on sensing results, the UE (re)selects some specific        sidelink resources and reserves multiple sidelink resources.

A UE is considered in-coverage on the carrier used for V2X sidelinkcommunication whenever it detects a cell on that carrier. If the UE thatis authorized for V2X sidelink communication is in-coverage on thefrequency used for V2X sidelink communication or if the gNB provides V2Xsidelink configuration for that frequency (including when the UE is outof coverage on that frequency), the UE uses the scheduled resourceallocation or UE autonomous resource selection as a per gNBconfiguration. When the UE is out of coverage on the frequency used forV2X sidelink communication and if the gNB does not provide V2X sidelinkconfiguration for that frequency, the UE may use a set of transmissionand reception resource pools pre-configured in the UE. V2X sidelinkcommunication resources are not shared with other non-V2X datatransmitted over the sidelink.

An RRC_CONNECTED UE may send a sidelink UE information message to theserving cell if it is interested in V2X sidelink communicationtransmission in order to request sidelink resources. If the UE isconfigured by upper layers to receive V2X sidelink communication and V2Xsidelink reception resource pools are provided, the UE receivescommunication on those provided resources.

For V2X sidelink communication, sidelink transmission and/or receptionresources including an exceptional pool for different frequencies forscheduled resource allocation and UE autonomous resource selection maybe provided. The sidelink resources for different frequencies can beprovided via dedicated signaling, system information block 21 (SIB21)and/or preconfiguration. The serving cell may indicate to the UE onlythe frequency on which the UE may acquire the resource configuration forV2X sidelink communication. If multiple frequencies and associatedresource information are provided, it is up to UE implementation toselect the frequency among the provided frequencies. The UE shall notuse preconfigured transmission resource if the UE detects a cellproviding resource configuration or inter-carrier resource configurationfor V2X sidelink communication. Frequencies which may provide V2Xsidelink communication resource configuration or cross-carrierconfiguration can be signaled in the SIB21 or pre-configured in the UE.The RRC_IDLE_UE may prioritize the frequency that provides cross-carrierresource configuration for V2X sidelink communication during cellreselection.

If the UE supports multiple transmission chains, it may simultaneouslytransmit on multiple carriers via PC5. When multiple frequencies for V2Xare supported, a mapping between V2X service types and V2X frequenciesis configured by upper layers. The UE should ensure a V2X service to betransmitted on the corresponding frequency. For scheduled resourceallocation, the gNB can schedule a V2X transmission on a frequency basedon the sidelink buffer status report (BSR), in which the UE includes thedestination index uniquely associated with a frequency reported by theUE to the gNB in a sidelink UE information message.

Bandwidth adaptation (BA) is supported in the 5G system. With BA, thereceive and transmit bandwidth of a UE does not need to be as large asthe bandwidth of the cell and can be adjusted. The width can be orderedto change, such as to narrow during a period of low activity to savepower. The location can move in the frequency domain, such as toincrease scheduling flexibility. The subcarrier spacing can be orderedto change, such as to enable different services.

A subset of the total cell bandwidth of a cell is referred to as abandwidth part (BWP) and BA is achieved by configuring the UE withBWP(s) and indicating to the UE which of the configured BWPs iscurrently the active BWP. A UE in an RRC-connected state is configuredwith one or more downlink (DL) and uplink (UL) BWPs for each configuredserving cell, such as a primary cell (PCell) or secondary cell (SCell).For an activated serving cell, there is always one active UL and DL BWPat any point in time. The BWP switching for a Serving Cell is used toactivate an inactive BWP and deactivate an active BWP at a time, and iscontrolled by the physical downlink control channel (PDCCH) indicating adownlink assignment or an uplink grant, by an bwp-InactivityTimer, byRRC signaling, or by a medium access control (MAC) entity itself uponinitiation of a random access procedure. Upon addition of a special cell(SpCell) or activation of the SCell, the DL BWP and UL BWP indicated byfirstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id respectively isactive without receiving a PDCCH indicating a downlink assignment or anuplink grant. The active BWP for a serving cell is indicated by eitherthe RRC or PDCCH. For the unpaired spectrum, a DL BWP is paired with aUL BWP, and BWP switching is common for both UL and DL. Upon expirationof a BWP inactivity timer, the UE switches the active DL BWP to thedefault DL BWP, or initial DL BWP if the default DL BWP is notconfigured.

Since the resource allocation mechanism in the prior art is deficient interms of handling multiple BWPs, there is a need in the art for anenhanced resource allocation mechanism for V2X sidelink communicationconsidering multiple BWPs on a carrier supporting sidelinkcommunication. The active BWP for sidelink communication can bedifferent from the active BWP for wider area network (WAN)communication. Sidelink communication can be supported on the same BWPas is used for WAN communication. The BWP inactivity timer consideringthe V2X sidelink communication also needs to be enhanced.

Each PDCCH monitoring occasion for system information (SI) messagereception in an SI window is associated with one of the transmittedsynchronization signal blocks (SSBs) (or SS/PBCH blocks). Based on thisassociation a UE can determine the PDCCH monitoring occasioncorresponding to one or more suitable SSBs, such as an SSB with asynchronization signal reference signal received power (SS-RSRP) above athreshold and monitor only these PDCCH monitoring occasions in an SIwindow.

In the existing system, a K^(th) PDCCH monitoring occasion for SImessage reception in the SI window corresponds to a K^(th) transmittedSSB, but this mapping rule between PDCCH monitoring occasions for SImessage reception in an SI window and transmitted SSBs works only if thenumber of PDCCH monitoring occasions for SI message reception in an SIwindow is equal to number of transmitted SSBs. Depending on the lengthof the SI window and other system information (OSI) search spaceconfiguration, the number of PDCCH monitoring occasions for SI messagereception in an SI window can be greater than the number of transmittedSSBs. Thus, there is also a need in the art for an enhanced mapping rulebetween PDCCH monitoring occasions in an SI window and transmitted SSBs.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the disclosure is to providea communication method and system for converging a 5G communicationsystem for supporting higher data rates beyond a 4G system.

Another aspect of the disclosure is to provide an enhanced resourceallocation mechanism for V2X sidelink communication considering multipleBWPs on a carrier supporting sidelink communication.

Another aspect of the disclosure is to provide an enhanced mapping rulebetween PDCCH monitoring occasions in an SI window and transmitted SSBs.In accordance with an aspect of the disclosure, a method performed by aterminal for acquiring an SI message is provided. The method includesreceiving, from a base station, a plurality of SSBs, determining atleast one PDCCH monitoring occasion associated with each of theplurality of SSBs in an SI window, and monitoring at least one PDCCHmonitoring occasion associated with at least one of the plurality ofSSBs to acquire the SI message.

In accordance with another aspect of the disclosure, a terminal in awireless communication system is provided. The terminal includes atransceiver, and a controller coupled with the transceiver andconfigured to control the transceiver to receive, from a base station, aplurality of SSBs, determine at least one PDCCH monitoring occasionassociated with each of the plurality of SSBs in an SI window, andmonitor at least one PDCCH monitoring occasion associated with at leastone of the plurality of SSBs to acquire an SI message.

In accordance with another aspect of the disclosure, a method performedby a base station for transmitting an SI message is provided. The methodincludes transmitting a plurality of SSBs to a terminal, andtransmitting the SI message to the terminal in at least one PDCCHmonitoring occasion in an SI window using a downlink beam correspondingto an SSB associated with the at least one PDCCH monitoring occasionamong the plurality of SSBs.

In accordance with another aspect of the disclosure, a base station in awireless communication system is provided. The base station includes atransceiver and a controller coupled with the transceiver. Thecontroller is configured to control the transceiver to transmit aplurality of SSBs to a terminal, and control the transceiver to transmitan SI message to the terminal in at least one PDCCH monitoring occasionin an SI window using a downlink beam corresponding to an SSB associatedwith the at least one PDCCH monitoring occasion among the plurality ofSSBs.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates a signaling flow between a UE and a gNB according toan embodiment;

FIG. 2 illustrates a signaling flow between a UE and a gNB according toan embodiment;

FIG. 3 illustrates a signaling flow between a UE and a gNB according toan embodiment;

FIG. 4 illustrates a signaling flow between a UE and a gNB according toan embodiment;

FIG. 5 illustrates a signaling flow between a UE and a gNB according toan embodiment;

FIG. 6 illustrates procedures for resource allocation of V2X sidelinkcommunication according to an embodiment;

FIG. 7 illustrates another example of procedures for resource allocationof V2X sidelink communication according to an embodiment;

FIG. 8 illustrates procedures for resource allocation of V2X sidelinkcommunication according to an embodiment;

FIG. 9 illustrates procedures for resource allocation of V2X sidelinkcommunication according to an embodiment;

FIG. 10 illustrates a cluster of SI-windows occurring periodically for acell transmitting 3 SI messages;

FIG. 11 illustrates mapping between PDCCH monitoring occasions for SImessage reception and SSBs according to a first embodiment;

FIG. 12 illustrates mapping between PDCCH monitoring occasions for SImessage reception and SSBs according to a second embodiment;

FIG. 13 is a block diagram of a terminal according to an embodiment ofthe disclosure; and

FIG. 14 is a block diagram of a base station according to an embodimentof the disclosure.

Throughout the drawings, like reference numerals will be understood torefer to like parts, components, and structures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of embodiments ofthe disclosure. It includes various specific details to assist in thatunderstanding, but these are to be regarded as examples. Accordingly,those of ordinary skill in the art will recognize that various changesand modifications of the embodiments described herein can be madewithout departing from the scope and spirit of the disclosure. Inaddition, descriptions of well-known functions and constructions may beomitted for the sake of clarity and conciseness.

The terms and words used in the following description and claims are notlimited to their dictionary meanings, but, are merely used to enable aclear and consistent understanding of the disclosure. Accordingly, itshould be apparent to those skilled in the art that the followingdetailed description is provided for illustration purposes only and notfor the purpose of limiting the disclosure.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

The term “substantially” indicates that the recited characteristic,parameter, or value need not be achieved exactly, but that deviations orvariations, such as tolerances, measurement error, measurement accuracylimitations and other factors known to those skilled in the art, mayoccur in amounts that do not preclude the effect the characteristic wasintended to provide.

As is known to those skilled in the art, blocks of a flowchart (orsequence diagram) and a combination of flowcharts may be represented andexecuted by computer program instructions that may be loaded on aprocessor of a general purpose computer, special purpose computer, orprogrammable data processing equipment. The loaded program instructions,when executed by the processor, create a means for performing functionsdescribed in the flowchart. Because the computer program instructionsmay be stored in a computer readable memory that is usable in aspecialized computer or a programmable data processing equipment, it isalso possible to create articles of manufacture that perform functionsdescribed in the flowchart. Because the computer program instructionsmay be loaded on a computer or programmable data processing equipment,when executed as processes, these instructions may perform operations offunctions described in the flowchart.

A block of a flowchart may correspond to a module, a segment, or a codecontaining one or more executable instructions implementing one or morelogical functions, or may correspond to a part thereof. In some cases,functions described by blocks may be executed in an order different fromthe listed order. For example, two blocks listed in sequence may besimultaneously executed or executed in reverse order.

In this description, the words “unit” and “module” may refer to asoftware component or hardware component, such as a field-programmablegate array (FPGA) or an application-specific integrated circuit (ASIC)capable of performing a function or an operation. However, a “unit”, orthe like, is not limited to hardware or software, and may be configuredto reside in an addressable storage medium or to drive one or moreprocessors. A “unit” may also refer to software components,object-oriented software components, class components, task components,processes, functions, attributes, procedures, subroutines, program codesegments, drivers, firmware, microcode, circuits, data, databases, datastructures, tables, arrays or variables. A function provided by acomponent and unit may be a combination of smaller components and unitsand may be combined with others to compose larger components and units.Components and units may be configured to drive a device or one or moreprocessors in a secure multimedia card.

Prior to the detailed description, terms or definitions necessary tounderstand the disclosure are described. However, these terms should beconstrued in a non-limiting manner.

A “base station (BS)” is an entity communicating with a UE and may bereferred to as a BS, base transceiver station (BTS), node B (NB),evolved NB (eNB), access point (AP), 5GNB, or gNB.

A “UE” is an entity communicating with a BS and may be referred to as aUE, device, mobile station (MS), mobile equipment (ME), or terminal.

Based on disclosed mapping between PDCCH monitoring occasions for SImessage reception and SSBs in an SI window herein, a UE can determine aPDCCH monitoring occasion corresponding to one or more suitable SSBs,such as an SSB with an SS-RSRP above a threshold, and monitor only thesePDCCH monitoring occasions in the SI-window irrespective of whether thenumber of PDCCH monitoring occasions in the SI window are greater thanor equal to the number of transmitted SSBs.

1. BWP Inactivity Timer Handling for V2X Sidelink (SL) Communication

Embodiment 1

FIG. 1 illustrates a signaling flow between a UE and a gNB according toan embodiment.

For an activated serving cell, if the UE (or MAC entity in the UE)receives a PDCCH addressed to an SL vehicle radio network temporaryidentifier (SL-V-RNTI) indicating SL grant, on the active DL BWP of thisserving cell, the UE starts or restarts the bwp-InactivityTimerassociated with the active DL BWP. In FIG. 1, the SL grant can be for SLcommunication based on LTE radio access technology (RAT) or NR RAT.

A UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by a gNB using RRCsignaling. There is one active DL BWP and active UL BWP for eachactivated serving cell. A UE interested in V2X SL communication sends asignaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL communication in step 110. The gNB assigns one ormore SL-V-RNTIs to the UE and sends an RRC connection reconfigurationmessage including the assigned one or more SL-V-RNTIs in step 120. TheUE monitors for a PDCCH addressed to the SL-V-RNTI in step 130. ThePDCCH addressed to the SL-V-RNTI indicates an SL grant for V2X SLcommunication.

If the UE receives a PDCCH addressed to the SL-V-RNTI on an active DLBWP, which is configured with a BWP identifier (ID) X, of a serving cellY, the UE starts or restarts a bwp-InactivityTimer associated with theactive DL BWP of serving cell Y in step 140. This operation is performedif a default DL BWP is configured and an active DL BWP is not thedefault DL BWP. This operation is also performed if a default DL BWP isnot configured and an active DL BWP is not the initial DL BWP.

Alternately, if the UE receives a PDCCH addressed to the SL-V-RNTI on anactive DL BWP, which is configured with BWP ID X, of a serving cell Y,and serving cell Y is a time division duplex (TDD) cell, the UE startsor restarts a bwp-InactivityTimer associated with the active DL BWP X ofserving cell Y. This operation is performed if a default DL BWP isconfigured and an active DL BWP is not the default DL BWP. Thisoperation is also performed if the default DL BWP is not configured andthe active DL BWP is not the initial DL BWP.

The above method is also performed for a PDCCH addressed to an SLsemi-persistent scheduling vehicle radio network temporary identifier(SL-SPS-V-RNTI). An NR gNB can configure the SL-SPS-V-RNTI separatelyfor SL communication based on the LTE RAT and NR RAT. The aboveoperation is also performed for a PDCCH addressed to the SL-SPS-V-RNTIfor SL communication based on the LTE RAT and on the NR RAT.

Embodiment 2

FIG. 2 illustrates a signaling flow between a UE and a gNB according toan embodiment. In FIG. 2, the SL grant can be for SL communication basedon the LTE RAT or NR RAT.

For an activated serving cell, if the UE receives a PDCCH addressed tothe SL-V-RNTI indicating SL grant, on the active DL BWP of this servingcell and there is no ongoing random access procedure associated withthis serving cell, the UE starts or restarts the bwp-InactivityTimerassociated with the active DL BWP.

The UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and UL BWP for each activatedserving cell. A UE interested in V2X SL communication sends a signalingmessage (e.g. SidelinkUEInformation message) to request resources forV2X SL communication in step 210. The gNB assigns one or more SL-V-RNTIsto the UE and sends an RRC connection reconfiguration message includingthe assigned one or more SL-V-RNTIs in step 220. The gNB sends a PDCCHaddressed to the SL-V-RNTI, and the UE monitors for the PDCCH addressedto the SL-V-RNTI in step 230. The PDCCH addressed to the SL-V-RNTIindicates an SL grant for V2X SL communication.

If the UE receives a PDCCH addressed to the SL-V-RNTI on an active DLBWP of a serving cell Y and there is no ongoing random access procedureassociated with serving cell Y, the UE starts or restarts abwp-InactivityTimer associated with the active DL BWP X of serving cellY in step 240. This operation is performed if the default DL BWP isconfigured and the active DL BWP is not the default DL BWP, and is alsoperformed if the default DL BWP is not configured and the active DL BWPis not the initial DL BWP.

Alternately, if the UE receives a PDCCH addressed to the SL-V-RNTI on anactive DL BWP of a serving cell Y and there is no ongoing random accessprocedure associated with serving cell Y and the serving cell is a TDDcell, the UE starts or restarts a bwp-InactivityTimer associated withthe active DL BWP X of serving cell Y This operation is performed if thedefault DL BWP is configured and the active DL BWP is not the default DLBWP, and is also performed if the default DL BWP is not configured andthe active DL BWP is not the initial DL BWP.

The above operation is also performed for a PDCCH addressed to theSL-SPS-V-RNTI. An NR gNB can configure the SL-SPS-V-RNTI separately forSL communication based on the LTE RAT and NR RAT. The above operation isalso performed for a PDCCH addressed to the SL-SPS-V-RNTI for SLcommunication based on the LTE RAT and on the NR RAT.

Embodiment 3

FIG. 3 illustrates a signaling flow between a UE and a gNB according toan embodiment. In FIG. 3, the SL grant can be for SL communication basedon the LTE RAT or NR RAT.

For an activated serving cell, if the UE receives a PDCCH addressed tothe SL-V-RNTI indicating SL grant, for the active DL BWP of this servingcell, the UE starts or restarts the bwp-InactivityTimer associated withthe active DL BWP.

The UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and UL BWP for each activatedserving cell. A UE interested in V2X SL communication sends a signalingmessage (e.g. SidelinkUEInformation message) to request resources forV2X SL communication in step 310. The gNB assigns one or more SL-V-RNTIsto the UE and sends an RRC connection reconfiguration message includingthe assigned one or more SL-V-RNTIs to the UE in step 320. The gNB sendsa PDCCH addressed to the SL-V-RNTI, and the UE monitors for the PDCCHaddressed to the SL-V-RNTI in step 330. The PDCCH addressed to theSL-V-RNTI indicates an SL grant for V2X SL communication.

If the UE receives a PDCCH addressed to the SL-V-RNTI on an active DLBWP of a serving cell Y indicating an SL grant for a BWP of serving cellZ, the UE starts or restarts a bwp-InactivityTimer associated with theactive DL BWP, which is configured with BWP ID Xl, of serving cell Z instep 340. This operation is performed if the default DL BWP isconfigured and the active DL BWP is not the default DL BWP, or if thedefault DL BWP is not configured and the active DL BWP is not theinitial DL BWP.

Alternately, if the UE receives a PDCCH addressed to the SL-V-RNTI on anactive DL BWP of a serving cell Y indicating an SL grant for a BWP ofserving cell Z and serving cell Z is a TDD cell, the UE starts orrestarts a bwp-InactivityTimer associated with the active DL BWP ofserving cell Z. This operation is performed if the default DL BWP isconfigured and the active DL BWP is not the default DL BWP, or if thedefault DL BWP is not configured and the active DL BWP is not theinitial DL BWP.

The above operation is also performed for a PDCCH addressed to theSL-SPS-V-RNTI. An NR gNB can configure the SL-SPS-V-RNTI separately forSL communication based on the LTE RAT and NR RAT. The above operation isalso performed for a PDCCH addressed to the SL-SPS-V-RNTI for SLcommunication based on the LTE RAT or on the NR RAT.

Embodiment 4

FIG. 4 illustrates a signaling flow between a UE and a gNB according toan embodiment. In FIG. 4, the SL grant can be for SL communication basedon the LTE RAT or NR RAT.

For an activated serving cell, if the UE receives a PDCCH addressed tothe SL-V-RNTI indicating an SL grant, for the active DL BWP of thisserving cell and there is no ongoing random access procedure associatedwith this serving cell, the UE starts or restarts thebwp-InactivityTimer associated with the active DL BWP.

The UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and UL BWP for each activatedserving cell. The UE interested in V2X SL communication sends asignaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL communication to the gNB in step 410. The gNBassigns one or more SL-V-RNTIs to the UE and sends an RRC connectionreconfiguration message including the assigned one or more SL-V-RNTIs tothe UE in step 420. The gNB sends a PDCCH addressed to the SL-V-RNTI,and the UE monitors for the PDCCH addressed to the SL-V-RNTI in step430. The PDCCH addressed to the SL-V-RNTI indicates an SL grant for V2XSL communication.

If the UE receives a PDCCH addressed to the SL-V-RNTI on an active DLBWP of a serving cell Y indicating an SL grant for a BWP of serving cellZ and there is no ongoing random access procedure associated withserving cell Z, the UE starts or restarts a bwp-InactivityTimerassociated with the active DL BWP of serving cell Z in step 440. Thisoperation is performed if the default DL BWP is configured and theactive DL BWP is not the default DL BWP, or if the default DL BWP is notconfigured and the active DL BWP is not the initial DL BWP.

Alternately, if the UE receives a PDCCH addressed to the SL-V-RNTI on anactive DL BWP of a serving cell Y indicating an SL grant for a BWP ofserving cell Z and serving cell Z is a TDD cell and there is no ongoingrandom access procedure associated with serving cell Z, the UE starts orrestarts a bwp-InactivityTimer associated with the active DL BWP ofserving cell Z. This operation is performed if the default DL BWP isconfigured and the active DL BWP is not the default DL BWP or if thedefault DL BWP is not configured and the active DL BWP is not theinitial DL BWP.

The above operation is also performed for a PDCCH addressed to theSL-SPS-V-RNTI. An NR gNB can configure the SL-SPS-V-RNTI separately forSL communication based on the LTE RAT and NR RAT. The above operation isalso performed for a PDCCH addressed to SL-SPS-V-RNTI for SLcommunication based on the LTE RAT or on the NR RAT.

Embodiment 5

FIG. 5 illustrates a signaling flow between a UE and a gNB according toan embodiment.

For an activated serving cell, if the UE transmits an SL MAC packet dataunit (PDU) using autonomous SL resources (i.e. by selecting resourcesfrom common transmission (TX) resource pools randomly or based onsensing) on an active BWP of this serving cell, the UE starts orrestarts the bwp-InactivityTimer associated with the active DL BWP ofthis serving cell.

The UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and UL BWP for each activatedserving cell. The UE interested in V2X SL communication sends asignaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL communication to the gNB in step 510. The gNBassigns one or more common TX resource pools to the UE and sends an RRCconnection reconfiguration message to the UE in step 520. The UE selectsthe resource from resource pool and transmits an SL MAC PDU in step 530.The gNB may also configure the SL SPS grants for V2X SL communication.The UE transmits an SL MAC PDU in SL SPS grants as well.

If the SL MAC PDU is transmitted on an active UL BWP of a serving cell,the UE starts or restarts a bwp-InactivityTimer associated with theactive DL BWP of this serving cell in step 540. This operation isperformed if the default DL BWP is configured and the active DL BWP isnot the default DL BWP, or if the default DL BWP is not configured andthe active DL BWP is not the initial DL BWP.

Alternately, if an SL MAC PDU is transmitted on an active UL BWP of aserving cell and serving cell is TDD cell, the UE starts or restarts abwp-InactivityTimer associated with the active DL BWP of this servingcell. This operation is performed if the default DL BWP is configuredand the active DL BWP is not the default DL BWP, or if the default DLBWP is not configured and the active DL BWP is not the initial DL BWP.

Embodiment 6

In an embodiment of the invention, for an activated serving cell, if theUE receives SL MAC PDU on an active BWP of this serving cell, the UEstarts or restarts the bwp-InactivityTimer associated with the active DLBWP of this serving cell.

UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and UL BWP for each activatedserving cell.

If an SL MAC PDU is received on an active UL BWP of a serving cell, theUE starts or restarts a bwp-InactivityTimer associated with the activeDL BWP of this serving cell. This operation is performed if the defaultDL BWP is configured and the active DL BWP is not the default DL BWP, orif the default DL BWP is not configured and the active DL BWP is not theinitial DL BWP.

Alternately, if an SL MAC PDU is received on an active UL BWP of aserving cell and serving cell is TDD cell, the UE starts or restarts abwp-InactivityTimer associated with the active DL BWP of this servingcell. This operation is performed if the default DL BWP is configuredand the active DL BWP is not the default DL BWP, or if the default DLBWP is not configured and the active DL BWP is not the initial DL BWP.

2. Resource Allocation for V2X SL Communication

Embodiment 1

The UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and one active UL BWP for eachactivated serving cell. The UE interested in V2X SL communication sendsa signaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL transmission. The UE indicates the one or morefrequencies for V2X SL transmission and list of V2X SL transmissiondestination(s). For scheduled resource allocation, the gNB assigns oneor more SL-V-RNTIs to the UE. The gNB also signals one or morev2x-SchedulingPools. Each v2x-SchedulingPool indicates a pool of Txresources for V2X SL communications. In the current design, eachsignaled v2x-SchedulingPool is associated with a carrier frequency(serving or non-serving) used for V2X SL communication.

The gNB signals one or more v2x-SchedulingPools for one or more carrierfrequencies for V2X SL communication or cells where eachv2x-SchedulingPool is associated with an UL BWP. In other words, the gNBsignals one or more v2x-SchedulingPools and for each scheduling poolindicates the associated carrier frequency (or cell list) and BWPinformation. The signaling of associated carrier frequency can beskipped for v2x-SchedulingPools associated with serving frequency (e.g.carrier frequency of special cell (SpCell)). For V2X SL transmission onone of the configured serving cells, a serving cell index can be usedinstead of carrier frequency information (i.e. absolute radio frequencychannel number (ARFCN)). One example of signaling v2x-SchedulingPoolsassociated with carrier frequency and BWP information is as follows:

EXAMPLE 1

List of BWPs is signaled by the gNB (e.g. in RRC Reconfigurationmessage). This list is per serving cell/frequency:

-   -   BWP configuration 1 (BWP ID, subcarrier spacing (SCS), location        and bandwidth of this BWP, etc.)    -   BWP configuration 2 (BWP ID, SCS, location and bandwidth of this        BWP, etc.)    -   BWP configuration 3 (BWP ID, SCS, location and bandwidth of this        BWP, etc.)    -   and so on.

List of v2x-SchedulingPools is signaled (e.g. in RRC Reconfigurationmessage)

-   -   v2x-SchedulingPool 1: carrier frequency, BWP ID,        v2x-SchedulingPool configuration parameters    -   v2x-SchedulingPool 2: carrier frequency, BWP ID,        v2x-SchedulingPool configuration parameters    -   v2x-SchedulingPool 3: carrier frequency, BWP ID,        v2x-SchedulingPool configuration parameters    -   and so on.

EXAMPLE 2

List of BWPs is signaled by the gNB (e.g. in RRC Reconfigurationmessage). This list is per serving cell/frequency:

-   -   BWP configuration 1 (BWP ID, SCS, location and bandwidth of this        BWP, etc.)    -   BWP configuration 2 (BWP ID, SCS, location and bandwidth of this        BWP, etc.)    -   BWP configuration 3 (BWP ID, SCS, location and bandwidth of this        BWP, etc.)    -   and so on.

List of v2x-SchedulingPools is signaled per frequency

List of frequencies is signaled by the gNB (e.g. in RRC Reconfigurationmessage):

-   -   Carrier frequency 1    -   v2x-SchedulingPool 1: BWP ID, v2x-SchedulingPool configuration    -   v2x-SchedulingPool 2: BWP ID, v2x-SchedulingPool configuration    -   v2x-SchedulingPool 3: BWP ID, v2x-SchedulingPool configuration    -   and so on.    -   Carrier frequency 2    -   v2x-SchedulingPool 1: BWP ID, v2x-SchedulingPool configuration    -   v2x-SchedulingPool 2: BWP ID, v2x-SchedulingPool configuration    -   v2x-SchedulingPool 3: BWP ID, v2x-SchedulingPool configuration    -   and so on.    -   Carrier frequency 3    -   v2x-SchedulingPool 1: BWP ID, v2x-SchedulingPool configuration    -   v2x-SchedulingPool 2: BWP ID, v2x-SchedulingPool configuration    -   v2x-SchedulingPool 3: BWP ID, v2x-SchedulingPool configuration    -   and so on.    -   and so on.

After receiving the v2x-SchedulingPool(s) from gNB, the UE monitors fora PDCCH addressed to the SL-V-RNTI. The DCI in the PDCCH addressed tothe SL-V-RNTI indicates an SL grant, i.e., Tx resources for V2X SLtransmission. The DCI includes resource info which indicates a Txresource allocated to the UE for V2X SL transmission. The Tx resourceindicated in the PDCCH is one of Tx resources from thev2x-SchedulingPool. In case multiple v2x-SchedulingPools associated withdifferent carrier frequencies are configured, the PDCCH indicates thecarrier frequency associated with SL grant using a carrier indicatorfield (CIF). For inter-carrier scheduled resource allocation, CIF=1 inDCI corresponds to the first entry in this frequency list, CIF=2corresponds to the second entry, and so on. CIF=0 in DCI corresponds tothe frequency where the DCI is received. The Tx resource indicated inthe PDCCH is one among the Tx resources from a v2x-SchedulingPoolcorresponding to a carrier frequency indicated by the CIF.

The DCI in the PDCCH addressed to the SL-V-RNTI also includes the BWPID. The Tx resource indicated in the PDCCH is one among the Tx resourcesfrom the v2x-SchedulingPool wherein v2x-SchedulingPool corresponds to acarrier frequency indicated by a CIF and UL BWP indicated by a BWP IDfield. The UE uses the received SL grant to transmit V2X SL transmissionon the UL BWP identified by the BWP ID of the carrier frequencyindicated by the CIF. One or more SL BWPs can be configured instead ofusing UL BWP for SL communication. This is in addition to DL and UL BWP.When two or more SL BWPs are configured, the PDCCH may include a BWP ID.The BWP ID included in the PDCCH indicates an SL BWP, wherein thev2x-SchedulingPool corresponds to the SL BWP. When only one SL BWP isconfigured, the PDCCH does not include a BWP ID and the Tx resourceindicated in the PDCCH is one among the Tx resources from av2x-SchedulingPool, wherein the v2x-SchedulingPool corresponds to SL BWPon a carrier frequency indicated by the CIF.

Upon receiving a PDCCH addressed to the SL-V-RNTI, the UE obtains a BWPID and CIF from DCI of the received PDCCH. The UE determines av2x-SchedulingPool corresponding to a carrier frequency indicated by theCIF and UL BWP indicated by a BWP ID field from one or morev2x-SchedulingPools configured by the gNB. The UE then uses the resourceinformation in the DCI to identify the Tx resource from the determinedv2x-SchedulingPool to be used for V2X SL transmission. The UE thenperforms V2X SL transmission on the UL BWP and carrier frequencyindicated in the DCI.

Upon receiving a PDCCH addressed to the SL-V-RNTI, the UE obtains a BWPID and CIF from DCI of the received PDCCH. The UE determines av2x-SchedulingPool corresponding to a carrier frequency indicated by theCIF and SL BWP indicated by BWP ID field from one or morev2x-SchedulingPools configured by the gNB. The UE then uses the resourceinformation in the DCI to identify the Tx resource from the determinedv2x-SchedulingPool to be used for V2X SL transmission, and performs V2XSL transmission on SL BWP of the carrier frequency indicated in the DCI.Note that the BWP ID can be skipped in the DCI if there is only one SLBWP per frequency.

If the carrier frequency for V2X SL transmission corresponding to thereceived SL grant corresponds to one of the activated serving cells andthe active UL BWP is not identical to the UL BWP of received SL grantand the UE cannot operate on multiple BWPs simultaneously, the UEswitches the active UL BWP to the UL BWP of the received SL grant andperforms the V2X SL transmission.

FIG. 6 illustrates procedures for resource allocation of V2X SLcommunication according to an embodiment.

Referring to FIG. 6, the UE interested in V2X SL communication sends asignaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL transmission to the gNB in step 610. In response tothe UE's request for V2X SL transmission resources, the gNB signals anSL-V-RNTI and four (4) v2x-SchedulingPools in step 620. Thev2x-SchedulingPool 1 is associated with carrier frequency F1 and a ULBWP with BWP ID 1. The v2x-SchedulingPool 2 is associated with carrierfrequency F1 and a UL BWP with BWP ID 4. The v2x-SchedulingPool 3 isassociated with carrier frequency F2 and a UL BWP with BWP ID 1. Thev2x-SchedulingPool 4 is associated with carrier frequency F2 and a ULBWP with BWP ID 2.

After receiving the v2x-SchedulingPools from gNB, the UE monitors for aPDCCH addressed to the SL-V-RNTI. The UE receives a PDCCH addressed tothe SL-V-RNTI in step 630. If the DCI indicates that an SL grant is forF2 and UL BWP 1, the UE then uses the resource information in the DCI toidentify the Tx resource from the determined v2x-SchedulingPool 3 to beused for V2X SL transmission in step 640. The UE then performs V2X SLtransmission based on the received SL grant on UL BWP 1 of the carrierfrequency F2 in step 650. One or more SL BWPs can be configured for SLcommunication instead of using a UL BWP for SL communication. In thiscase the procedure is applied by replacing ‘UL BWP’ with ‘SL BWP’.

In response to the UE's request for V2X SL transmission resources, thegNB signals SL-V-RNTI and 4 v2x-SchedulingPools. The v2x-SchedulingPool1 is associated with carrier frequency F1 and an SL BWP with BWP ID 1.The v2x-SchedulingPool 2 is associated with carrier frequency F1 and anSL BWP with BWP ID 4. The v2x-SchedulingPool 3 is associated withcarrier frequency F2 and an SL BWP with BWP ID 1. The v2x-SchedulingPool4 is associated with carrier frequency F2 and an SL BWP with BWP ID 2.

After receiving the v2x-SchedulingPools from gNB, the UE monitors for aPDCCH addressed to the SL-V-RNTI. The UE receives a PDCCH addressed tothe SL-V-RNTI. The DCI indicates that an SL grant is for F2 and SL BWP1. The UE then uses the resource information in the DCI to identify theTx resource from the determined v2x-SchedulingPool 3 to be used for V2XSL transmission. The UE then performs V2X SL transmission based onreceived SL grant on SL BWP 1 of the carrier frequency F2.

FIG. 7 illustrates another example of procedures for resource allocationof V2X SL communication according to an embodiment.

Referring to FIG. 7, the UE interested in V2X SL communication sends asignaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL transmission in step 710. In response to the UE'srequest for V2X SL transmission resources, the gNB signals SL-V-RNTI andfour (4) v2x-SchedulingPools for a carrier frequency of one of servingcells in step 720. The v2x-SchedulingPool 1 is associated a UL BWP withBWP ID 1. The v2x-SchedulingPool 2 is associated with a UL BWP with BWPID 2. The v2x-SchedulingPool 3 is associated with a UL BWP with BWP ID3. The v2x-SchedulingPool 4 is associated with a UL BWP with BWP ID 4.

After receiving the v2x-SchedulingPools from the gNB, the UE monitorsfor a PDCCH addressed to the SL-V-RNTI. The UE receives a PDCCHaddressed to the SL-V-RNTI from the gNB in step 730. The DCI is receivedon a carrier frequency for which v2x-SchedulingPools are configured. IfDCI indicates that the SL grant is for UL BWP 1, the UE then uses theresource information in the DCI to identify the Tx resource from thedetermined v2x-SchedulingPool 1 to be used for V2X SL transmission instep 740. The UE then performs V2X SL transmission based on the receivedSL grant on UL BWP 1 of the carrier frequency on which the DCI wasreceived in step 750.

One or more SL BWPs can be configured for SL communication instead ofusing a UL BWP for SL communication. In this case, the procedure isapplied by replacing ‘UL BWP’ with ‘SL BWP’. In response to the UE'srequest for V2X SL transmission resources, the gNB signals an SL-V-RNTIand 4 v2x-SchedulingPools for a carrier frequency of one of servingcells. The v2x-SchedulingPool 1 is associated with an SL BWP with BWP ID1. The v2x-SchedulingPool 2 is associated with an SL BWP with BWP ID 2.The v2x-SchedulingPool 3 is associated with an SL BWP with BWP ID 3. Thev2x-SchedulingPool 4 is associated with an SL BWP with BWP ID 4. Afterreceiving the v2x-SchedulingPools from gNB, the UE monitors for a PDCCHaddressed to the SL-V-RNTI. The UE receives a PDCCH addressed to theSL-V-RNTI. The DCI is received on a carrier frequency for whichv2x-SchedulingPools are configured and indicates that an SL grant is foran SL BWP 1. The UE then uses the resource information in the DCI toidentify the Tx resource from the determined v2x-SchedulingPool 1 to beused for V2X SL transmission. The UE then performs V2X SL transmissionbased on the received SL grant on SL BWP 1 of the carrier frequency onwhich the DCI was received.

Embodiment 2

The UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and one active UL BWP for eachactivated serving cell. The UE interested in V2X SL communication sendsa signaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL transmission. The UE indicates the one or morefrequencies for V2X SL transmission and a list of V2X SL transmissiondestination(s). For scheduled resource allocation, the gNB assigns oneor more SL-V-RNTIs to the UE. The gNB also signals one or morev2x-SchedulingPools, where each v2x-SchedulingPool indicates a pool ofTx resources for V2X SL communications. In the current design, eachsignaled v2x-SchedulingPool is associated with a carrier frequency(serving or non-serving) used for V2X SL communication.

After receiving the v2x-SchedulingPool from gNB, the UE monitors for aPDCCH addressed to the SL-V-RNTI. The DCI in the PDCCH addressed to theSL-V-RNTI indicates an SL grant, i.e., Tx resource for V2X SLcommunication. The DCI includes resource info which indicates the Txresource assigned to the UE for V2X SL transmission. The Tx resourceindicated in the PDCCH is one of Tx resources from v2x-SchedulingPool.In case multiple v2x-SchedulingPools associated with different carrierfrequencies are configured, PDCCH indicates the carrier frequencyassociated with SL grant using CIF. For inter-carrier scheduled resourceallocation, CIF=1 in the DCI corresponds to the first entry in thisfrequency list, CIF=2 corresponds to the second entry, and so on. CIF=0in the DCI corresponds to the frequency where the DCI is received. TheTx resource indicated in the PDCCH is one among the Tx resources fromv2x-SchedulingPool corresponding to frequency indicated by the CIF.

In an embodiment of the disclosure, DCI in the PDCCH addressed to theSL-V-RNTI also includes the BWP ID. The Tx resource indicated in thePDCCH is one among Tx resources from v2x-SchedulingPool corresponding toa carrier frequency indicated by the CIF. The UE will use the receivedSL grant to transmit V2X SL transmission on UL BWP identified by BWP IDof the carrier frequency indicated by the CIF. It is to be noted thatone or more SL BWPs can be configured for SL communication instead ofusing UL BWP for SL communication. The UE will use the received SL grantto transmit V2X SL transmission on SL BWP identified by BWP ID of thecarrier frequency indicated by the CIF.

Upon receiving a PDCCH addressed to the SL-V-RNTI, the UE obtains a BWPID and CIF from DCI of the received PDCCH. The UE determines av2x-SchedulingPool corresponding to a carrier frequency indicated by theCIF from one or more v2x-SchedulingPools configured by the gNB. The UEthen uses the resource information in the DCI to identify the Txresource from the determined v2x-SchedulingPool to be used for V2X SLtransmission. The UE then performs V2X SL transmission on UL BWP andcarrier frequency indicated in the DCI. It is to be noted that one ormore SL BWPs can be configured for SL communication instead of using ULBWP for SL communication. In this case BWP ID in the DCI refers to SLBWP. The UE will use the received SL grant to transmit V2X SLtransmission on SL BWP identified by BWP ID of the carrier frequencyindicated by the CIF.

If the carrier frequency for V2X SL transmission corresponding to thereceived SL grant corresponds to one of the activated serving cells andthe active UL BWP is not identical to UL BWP of received SL grant andthe UE cannot operate on multiple BWP simultaneously, the UE switchesthe active UL BWP to UL BWP of the received SL grant and performs theV2X SL transmission.

FIG. 8 illustrates procedures for resource allocation of V2X SLcommunication according to an embodiment.

Referring to FIG. 8, the UE interested in V2X SL communication sends asignaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL transmission in step 810. In response to the UE'srequest for V2X SL transmission resources, gNB signals SL-V-RNTI and two(2) v2x-SchedulingPools in step 820. The v2x-SchedulingPool 1 isassociated with carrier frequency F1. The v2x-SchedulingPool 2 isassociated with carrier frequency F2. After receiving thev2x-SchedulingPools from gNB, the UE monitors for a PDCCH addressed tothe SL-V-RNTI. The UE receives a PDCCH addressed to the SL-V-RNTI instep 830. If the DCI indicates that SL grant is for F2 and UL BWP 2, theUE then uses the resource information in the DCI to identify the Txresource from the v2x-SchedulingPool 2 corresponding to a carrierfrequency F2 indicated in the DCI in step 840. The UE then performs V2XSL transmission based on the received SL grant on UL BWP 2 (indicated inthe DCI) of the carrier frequency F2 (indicated in the DCI) in step 850.It is to be noted that one or more SL BWPs can be configured for SLcommunication instead of using UL BWP for SL communication. In this casethe procedure is applied by replacing ‘UL BWP’ with ‘SL BWP’. Inresponse to the UE's request for V2X SL transmission resources, gNBsignals SL-V-RNTI and two (2) v2x-SchedulingPools in step 820. Thev2x-SchedulingPool 1 is associated with carrier frequency F1. Thev2x-SchedulingPool 2 is associated with carrier frequency F2. Afterreceiving the v2x-SchedulingPools from gNB, the UE monitors for a PDCCHaddressed to the SL-V-RNTI. The UE receives a PDCCH addressed to theSL-V-RNTI in step 830. If the DCI indicates that SL grant is for F2 andSL BWP 2, the UE then uses the resource information in the DCI toidentify the Tx resource from the v2x-SchedulingPool 2 corresponding toa carrier frequency F2 indicated in the DCI in step 840. The UE thenperforms V2X SL transmission based on the received SL grant on SL BWP 2(indicated in the DCI) of the carrier frequency F2 (indicated in theDCI) in step 850.

Embodiment 3

UE is configured with one or more serving cells. For each activatedserving cell, one or more BWPs are configured by the gNB using RRCsignaling. There is one active DL BWP and one active UL BWP for eachactivated serving cell. The UE interested in V2X SL communication sendsa signaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL transmission. The UE indicates the one or morefrequencies for V2X SL transmission and list of V2X SL transmissiondestination(s). For scheduled resource allocation, gNB assigns one ormore SL-V-RNTIs to the UE. The gNB also signals one or morev2x-SchedulingPools, where each v2x-SchedulingPool indicates a pool ofTx resources for V2X SL communications. In the current design, eachsignaled v2x-SchedulingPool is associated with a carrier frequency usedfor V2X SL communication.

The v2x-SchedulingPools signaled by the gNB are also associated with ULBWPs. For each carrier frequency, there is at most onev2x-SchedulingPool and each v2x-SchedulingPool is associated with a ULBWP. The associated UL BWP is signaled by the gNB. The differencebetween this Embodiment 3 and Embodiment 1 described above is that inEmbodiment 1, for each carrier frequency, multiple v2x-SchedulingPoolscan be configured where each is associated with a different UL BWP. Itis to be noted that one or more SL BWPs can be configured for SLcommunication instead of using a UL BWP for SL communication. In thiscase, v2x-SchedulingPools signaled by the gNB are also associated withSL BWPs. For each carrier frequency, there is at most onev2x-SchedulingPool and each v2x-SchedulingPool is associated with an SLBWP. The associated SL BWP is signaled by the gNB. The differencebetween this Embodiment 3 and Embodiment 1 described above is that inEmbodiment 1, for each carrier frequency multiple v2x-SchedulingPoolscan be configured where each is associated with a different SL BWP.

After receiving the v2x-SchedulingPool from gNB, the UE monitors for aPDCCH addressed to the SL-V-RNTI. The DCI in the PDCCH addressed to theSL-V-RNTI indicates an SL grant, i.e., Tx resource for V2X SLcommunication. The DCI includes resource info which indicates the Txresource assigned to the UE for V2X SL communication. The Tx resourceindicated in the PDCCH is one among the Tx resources from thev2x-SchedulingPool. When multiple v2x-SchedulingPools associated withdifferent carrier frequencies are configured, PDCCH indicates thecarrier frequency associated with the SL grant using a CIF. Forinter-carrier scheduled resource allocation, CIF=1 in the DCIcorresponds to the first entry in this frequency list, CIF=2 correspondsto the second entry, and so on. CIF=0 in the DCI corresponds to thefrequency where the DCI is received. The Tx resource indicated in thePDCCH is one of Tx resources from v2x-SchedulingPool corresponding tofrequency indicated by the CIF.

Upon receiving a PDCCH addressed to the SL-V-RNTI, the UE obtains CIFfrom DCI of the received PDCCH. The UE determines a v2x-SchedulingPoolcorresponding to a carrier frequency indicated by the CIF from one ormore v2x-SchedulingPools configured by the gNB. The UE then uses theresource information in the DCI to identify the Tx resource from thedetermined v2x-SchedulingPool to be used for V2X SL transmission. The UEthen performs V2X SL transmission on a UL BWP associated with thedetermined v2x-SchedulingPool. It is to be noted that one or more SLBWPs can be configured for SL communication instead of using the UL BWPfor SL communication. In this case, the UE performs V2X SL transmissionon SL BWP associated with the determined v2x-SchedulingPool.

If the carrier frequency for V2X SL transmission corresponding to thereceived SL grant corresponds to one of the activated serving cells andthe active UL BWP is not identical to UL BWP of received SL grant andthe UE cannot operate on multiple BWPs simultaneously, the UE switchesthe active UL BWP to a UL BWP of the received SL grant and performs theV2X SL transmission.

FIG. 9 illustrates procedures for resource allocation of V2X SLcommunication according to an embodiment.

Referring to FIG. 9, the UE interested in V2X SL communication sends asignaling message (e.g. SidelinkUEInformation message) to requestresources for V2X SL transmission to the gNB in step 910. In response tothe UE's request for V2X SL transmission resources, the gNB sendsSL-V-RNTI and two (2) v2x-SchedulingPools to the UE in step 920. Thev2x-SchedulingPool 1 is associated with carrier frequency F1 and a ULBWP with BWP ID 1. The v2x-SchedulingPool 2 is associated with carrierfrequency F2 and a UL BWP with BWP ID 4.

After receiving the v2x-SchedulingPools from the gNB, the UE monitorsfor a PDCCH addressed to the SL-V-RNTI. The UE receives a PDCCHaddressed to the SL-V-RNTI in step 930. If the DCI indicates that SLgrant is for F2, the UE then uses the resource information in the DCI toidentify the scheduling assignment (SA), which also refers to‘scheduling control,’ and data resources from the determinedv2x-SchedulingPool 2 (corresponding to a carrier frequency F2) to beused for V2X SL transmission in step 940. The UE then performs V2X SLtransmission based on the received SL grant on UL BWP 4 of the carrierfrequency F2 in step 950. One or more SL BWPs can be configured for SLcommunication instead of using a UL BWP for SL communication. In thiscase, the procedure is applied by replacing a ‘UL BWP’ with ‘SL BWP’.The UE interested in V2X SL communication sends a signaling message(e.g. SidelinkUEInformation message) to request resources for V2X SLtransmission in step 910. In response to the UE's request for V2X SLtransmission resources, the gNB sends an SL-V-RNTI and two (2)v2x-SchedulingPools to the UE in step 920. The v2x-SchedulingPool 1 isassociated with carrier frequency F1 and an SL BWP with BWP ID 1. Thev2x-SchedulingPool 2 is associated with carrier frequency F2 and an SLBWP with BWP ID 4.

After receiving the v2x-SchedulingPools from the gNB, the UE monitorsfor a PDCCH addressed to the SL-V-RNTI. The UE receives a PDCCHaddressed to the SL-V-RNTI in step 930. If the DCI indicates that the SLgrant is for F2, the UE then uses the resource information in the DCI toidentify the SA and data resources from the determinedv2x-SchedulingPool 2 (corresponding to a carrier frequency F2) to beused for V2X SL transmission in step 940. The UE then performs V2X SLtransmission based on the received SL grant on UL BWP 4 of the carrierfrequency F2 in step 950.

Mapping Between PDCCH Monitoring Occasion in SI Window and SSBs

In the 5G wireless communication system, system information is dividedinto minimum SI (comprising of MIB and SIB1) and other SI (SIB 2, SIB 3and so on). SIBs other than SIB1 are carried in SystemInformation (SI)messages, which are transmitted on the DL-SCH. Only SIBs having the sameperiodicity can be mapped to the same SI message. Each SI message istransmitted within periodically occurring time domain windows (referredto as SI windows with same lengths for all SI messages). Each SI messageis associated with an SI window and the SI windows of different SImessages do not overlap. That is, within one SI window only thecorresponding SI message is transmitted. A schedulingInfoList insi-SchedulingInfo in SIB1 includes a list of SI messages transmitted bythe gNB. SIB1 indicates the mapping between SIBs and SI messages, andthe periodicity of each transmitted SI message and length of the SIwindow.

In NR, a cluster of SI windows (each of equal length) occursperiodically (at smallest SI period amongst all the SI periods).

FIG. 10 illustrates a cluster of SI-windows occurring periodically for acell transmitting 3 SI messages.

Referring to FIG. 10, a cell transmits 3 SI messages (i.e.,schedulingInfoList in si-SchedulingInfo in SIB1 includes a list of 3 SImessages) wherein SI message 1 has an SI periodicity of 80 ms, SImessage 2 has an SI periodicity of 160 ms and SI message 3 hasperiodicity of 240 ms. SI message 1 is mapped to SI window number 1. SImessage 2 is mapped to SI window number 2 and SI message 3 is mapped toSI window number 3. For an SI message, SI window number is the order ofentry in the list of SI messages configured by schedulingInfoList insi-SchedulingInfo in SIB1.

For acquiring an SI message, the UE determines the location of SIwindows of that SI message as follows: SI window for an SI messagestarts at the slot #a, where a=x mod N, in the radio frame for which SFNmod T=FLOOR(x/N), where T is the si-Periodicity of the SI message and Nis the number of slots in a radio frame and x=(n1)*w, where w is the SIwindowLength and n is the SI window number. For an SI message, SI windownumber is the order of entry in the list of SI messages configured byschedulingInfoList in si-SchedulingInfo in SIB1.

For acquiring the SI message, in the SI window of that SI message, theUE monitors the PDCCH monitoring occasions (i.e. symbols/slots)configured for SI message reception. For SI message acquisition, PDCCHmonitoring occasion(s) are determined according to osi-searchSpace.There can be one or more DL bandwidth parts in a cell. For SI message(s)reception in a DL BWP, osi-searchSpace is signaled by the gNB in a DLBWP configuration of that BWP. For an initial DL BWP, osi-searchSpace issignaled in an SIB1 and dedicated RRC signaling. For other dedicated DLBWPs, osi-searchSpace is signaled in dedicated RRC signaling.

If osi-searchSpace is set to zero (also referred as defaultassociation), PDCCH monitoring occasions for SI message reception in SIwindow are identical to PDCCH monitoring occasions for SIB 1. PDCCHmonitoring occasions for SIB1 are indicated using the parameters searchspace zero and control resource set (coreset) zero in MIB. Ifosi-searchSpace is not set to zero (also referred as non-defaultassociation), PDCCH monitoring occasions for SI message is determinedbased on a search space configuration indicated by osi-searchSpace.

The search space configuration indicated by osi-searchSpace comprises ofparameters Monitoring-periodicity-PDCCH-slot,Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot andduration. A UE determines a PDCCH monitoring occasion from the PDCCHmonitoring periodicity (Monitoring-periodicity-PDCCH-slot), the PDCCHmonitoring offset (Monitoring-offset-PDCCH-slot), and the PDCCHmonitoring pattern (Monitoring-symbols-PDCCH-within-slot) within a slot.PDCCH monitoring occasions are in slots ‘x’ to x+duration where the slotwith number ‘x’ in a radio frame with number ‘y’ satisfies the followingEquation (1):(y*(number of slots in a radio frame)+x−Monitoring-offset-PDCCH-slot)mod(Monitoring-periodicity-PDCCH-slot)=0;  (1)

The starting symbol of a PDCCH monitoring occasion in each slot havingPDCCH monitoring occasion is given byMonitoring-symbols-PDCCH-within-slot. The length (in symbols) of a PDCCHmonitoring occasion is given in the coreset associated with the searchspace. Based on search space configuration indicated by osi-searchSpace(comprising of parameters Monitoring-periodicity-PDCCH-slot,Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot andduration), the UE can determine the PDCCH monitoring occasions for SImessage reception in the SI window.

In a TDD cell, a UE receives TDD configuration using at least one oftdd-UL-DL-ConfigurationCommon IE, tdd-UL-DL-ConfigurationDedicated IEand group common PDCCH. tdd-UL-DL-ConfigurationCommon IE is signaled insystem information and indicates DL symbols, UL symbols and flexiblesymbols. tdd-UL-DL-ConfigurationDedicated IE is signaled in dedicatedRRC signaling and indicates which of the flexible symbols are ULsymbols. Group common PDCCH provides TDD configuration for one or moreslots. Among the PDCCH monitoring occasions signaled by osi-searchSpace,the UE excludes those PDCCH monitoring occasion(s) which are overlappingwith UL symbol(s). The UL symbol(s) are determined according totdd-UL-DL-ConfigurationCommon. Note that exclusion of monitoringoccasions which are overlapping with UL symbols determined according totdd-UL-DL-ConfigurationCommon parameter is performed only in a TDD cellwhen an FDD cell tdd-UL-DL-ConfigurationCommon is not signaled.

Each PDCCH monitoring occasion for SI message reception in an SI windowis associated with one of the transmitted SSBs (or SS/PBCH blocks).Based on this association a UE can determine a PDCCH monitoring occasioncorresponding to one or more suitable SSBs (e.g. SSB with SS-RSRP abovea threshold) and monitor only these PDCCH monitoring occasions in the SIwindow. In the existing system, K^(th) PDCCH monitoring occasion for SImessage reception in an SI window corresponds to K^(th) transmitted SSB.However, this mapping rule between PDCCH monitoring occasions for SImessage reception in the SI window and transmitted SSBs works only ifthe number of PDCCH monitoring occasions for SI message reception in anSI window is equal to the number of transmitted SSBs. However, dependingon the length of the SI window and OSI search space configuration, thenumber of PDCCH monitoring occasions for SI message reception in the SIwindow can be greater than the number of transmitted SSBs. Thus, anenhanced mapping rule between PDCCH monitoring occasions in the SIwindow and transmitted SSBs is needed.

There are up to 64 SSBs and each SSB is uniquely identified by an SSBidentifier. The parameter ssb-PositionsInBurst in SystemInformationBlock1 indicates which SSBs are transmitted by the gNB. ssb-PositionsInBurstis a bitmap. The first/leftmost bit in ssb-PositionsInBurst correspondsto SS/PBCH block index 0, the second bit corresponds to SS/PBCH blockindex 1, and so on. Value 0 in the bitmap indicates that thecorresponding SS/PBCH block is not transmitted while value 1 indicatesthat the corresponding SS/PBCH block is transmitted. The PDCCHmonitoring occasions for paging which are not overlapping with ULsymbols (UL symbols are determined according totdd-UL-DL-ConfigurationCommon parameter signaled in SIB1) aresequentially numbered from one in the SI window. The valid PDCCHmonitoring occasions in the SI window are sequentially numbered from 1in the SI window. These numbered PDCCH monitoring occasions are thenmapped to SSBs as follows:

First embodiment: (x*N+K)^(th) PDCCH monitoring occasion(s) in the SIwindow corresponds to K^(th) transmitted SSB

N is the number of transmitted SSBs. K=1, 2, . . . N;

x=0, 1, . . . X−1; X=(Number of PDCCH monitoring occasions in SIWindow/N). Note X is rounded up to the nearest integer having a greaterthan or equal value if the division (Number of PDCCH monitoringoccasions in SI Window/N) is not an integer.

Note that the actual transmitted SSBs are sequentially numbered from 1to N in ascending order of their SSB Indices. For example, presumingthat ssb-PositionsInBurst indicates that SSB Index 4, SSB Index 8, SSBIndex 14 and SSB Index 16 are transmitted by the gNB, K equals 1 for SSBwith SSB Index 4, K equals 2 for SSB with SSB Index 8, K equals 3 forSSB with SSB index 14, and K equals 4 for SSB with SSB Index 16.

FIG. 11 illustrates mapping between PDCCH monitoring occasions for SImessage reception and SSBs according to a first embodiment. There are 4transmitted SSBs and the number of PDCCH monitoring occasions in the SIwindow is 8. SSB 1 (i.e. SSB corresponding to K equals 1) is mapped to1st (0*4+1) and 5th (1*4+1) PDCCH monitoring occasions. SSB 2 (i.e. SSBcorresponding to K equals 2) is mapped to 2nd (0*4+2) and 6th (1*4+2)PDCCH monitoring occasions. SSB 3 (i.e. SSB corresponding to K equals 3)is mapped to 3rd (0*4+3) and 7th (1*4+3) PDCCH monitoring occasions. SSB4 (i.e. SSB corresponding to K equals 4) is mapped to 4th (0*4+4) and8th (1*4+4) PDCCH monitoring occasions.

Second embodiment: ((K−1)*X+x)th PDCCH monitoring occasion(s) in an SIwindow corresponds to a Kth transmitted SSB

N is the number of transmitted SSBs. K=1, 2, . . . N;

x=1, 2 . . . , X; X=(Number of PDCCH monitoring occasions in SIWindow/N). Note X is rounded up to nearest integer having a greater thanor equal value if the division (Number of PDCCH monitoring occasions inSI Window/N) is not an integer.

Note that the actual transmitted SSBs are sequentially numbered from 1to N in ascending order of their SSB Indices. For example, presuming assb-PositionsInBurst indicates that SSB Index 4, SSB Index 8, SSB Index14 and SSB Index 16 are transmitted by the gNB. As such, K equals 1 forSSB with SSB Index 4, K equals 2 for SSB with SSB Index 8, K equals 3for SSB with SSB index 14 and K equals 4 for SSB with SSB Index 16.

FIG. 12 illustrates mapping between PDCCH monitoring occasions for SImessage reception and SSBs according to a second embodiment. There are 4transmitted SSBs and the number of PDCCH monitoring occasions in the SIwindow is 8. SSB 1 (i.e. SSB corresponding to K equals 1) is mapped to1st ((1−1)*2+1) and 2nd ((1−1)*2+2) PDCCH monitoring occasions. SSB 2(i.e. SSB corresponding to K equals 2) is mapped to 3rd ((2−1)*2+1) and4th ((2−1)*2+2) PDCCH monitoring occasions. SSB 3 (i.e. SSBcorresponding to K equals 3) is mapped to 5th ((3−1)*2+1) and 6th((3−1)*2+2) PDCCH monitoring occasions. SSB 4 (i.e. SSB corresponding toK equals 4) is mapped to 7th ((4−1)*2+1) and 8th ((4−1)*2+2) PDCCHmonitoring occasions.

Based on mapping between PDCCH monitoring occasions for SI messagereception and SSBs in the SI window as explained above, the UE candetermine PDCCH monitoring occasions corresponding to one or moresuitable SSBs (e.g. SSB with SS-RSRP above a threshold) and monitor onlythese PDCCH monitoring occasions in the SI window. Based on mappingbetween PDCCH monitoring occasions for SI message reception and SSBs inthe SI window as explained above, the gNB transmits a PDCCH addressed toan SI-RNTI in the PDCCH monitoring occasions in the SI window using theDL beam corresponding to the SSB associated with that PDCCH monitoringoccasion.

FIG. 13 is a block diagram of a terminal according to an embodiment ofthe disclosure.

Referring to FIG. 13, a terminal includes a transceiver 1310, acontroller 1320 and a memory 1330. The controller 1320 may refer to acircuitry, an ASIC, or at least one processor. The transceiver 1310, thecontroller 1320 and the memory 1330 are configured to perform theoperations of the UE illustrated in the figures, e.g. FIGS. 1 to 12, oras otherwise described above. Although the transceiver 1310, thecontroller 1320 and the memory 1330 are shown as separate entities, theymay be realized as a single entity like a single chip. The transceiver1310, the controller 1320 and the memory 1330 may also be electricallyconnected to or coupled with each other.

The transceiver 1310 may transmit and receive signals to and from othernetwork entities, e.g., a base station.

The controller 1320 may control the UE to perform functions according toone of the embodiments described above. For example, the controller 1320is configured to control the transceiver 1310 to receive information ontransmitted SSBs (e.g. ssb-PositionsInBurst) and configurationinformation on search space for SI message reception (e.g.osi-searchSpace) from a base station in SIB 1. The controller 1320 isconfigured to control the transceiver 1310 to receive a plurality ofSSBs from the base station. The plurality of SSBs is indicated by theinformation on transmitted SSBs. The controller 1320 is configured todetermine at least one PDCCH monitoring occasion associated with each ofthe plurality of SSBs in an SI window. The PDCCH monitoring occasions isindicated by the configuration information on search space for SImessage reception. In addition, in order to determine the at least onePDCCH monitoring occasion, the controller 1320 may be further configuredto sequentially number the at least one PDCCH monitoring occasion in theSI window from one, sequentially number the plurality of SSBs inascending order of SSB indexes of the plurality of SSBs from one, andmap an (x*N+K)th PDCCH monitoring occasion of the at least one PDCCHmonitoring occasion in the SI window to a Kth SSB of the plurality ofSSBs. The controller 1320 is configured to monitor at least one PDCCHmonitoring occasion associated with at least one of the plurality ofSSBs, and acquire the SI message.

In an embodiment, the operations of the terminal may be implementedusing the memory 1330 storing corresponding program codes. Specifically,the terminal may be equipped with the memory 1330 to store program codesimplementing desired operations. To perform the desired operations, thecontroller 1320 may read and execute the program codes stored in thememory 1330 by using a processor or a central processing unit (CPU).

FIG. 14 is a block diagram of a base station according to an embodimentof the disclosure.

Referring to FIG. 14, a base station includes a transceiver 1410, acontroller 1420 and a memory 1430. The controller 1420 may refer to acircuitry, an ASIC, or at least one processor. The transceiver 1410, thecontroller 1420 and the memory 1430 are configured to perform theoperations of the network (e.g., gNB) illustrated in the figures, e.g.FIGS. 1 to 12, or as otherwise described above. Although the transceiver1410, the controller 1420 and the memory 1430 are shown as separateentities, they may be realized as a single entity like a single chip.The transceiver 1410, the controller 1420 and the memory 1430 may alsobe electrically connected to or coupled with each other.

The transceiver 1410 may transmit and receive signals to and from othernetwork entities, e.g., a terminal.

The controller 1420 may control the base station to perform functionsaccording to one of the embodiments described above. For example, thecontroller 1420 is configured to control the transceiver 1410 totransmit information on transmitted SSBs and configuration informationon a search space for SI message reception to a terminal in SIB 1. Inaddition, the controller 1420 is configured to control the transceiver1410 to transmit a plurality of SSBs and an SI message to the terminalin at least one PDCCH monitoring occasion in an SI window using adownlink beam corresponding to an SSB associated with the at least onePDCCH monitoring occasion among the plurality of SSBs.

In an embodiment, the operations of the base station may be implementedusing the memory 1430 storing corresponding program codes. Specifically,the base station may be equipped with the memory 1430 to store programcodes implementing desired operations. To perform the desiredoperations, the controller 1420 may read and execute the program codesstored in the memory 1430 by using a processor or a CPU.

While the disclosure has been shown and described with reference toembodiments thereof, it will be understood by those skilled in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the disclosure as defined by theappended claims and their equivalents.

What is claimed is:
 1. A method performed by a terminal for acquiring a system information (SI) message, comprising: receiving, from a base station, a plurality of synchronization signal blocks (SSBs); identifying at least one physical downlink control channel (PDCCH) monitoring occasion associated with each of the plurality of SSBs in an SI window, wherein an (x*N+K)th PDCCH monitoring occasion of the at least one PDCCH monitoring occasion in the SI window is mapped to a Kth SSB of the plurality of SSBs, where the at least one PDCCH monitoring occasion in the SI window is sequentially numbered from one, the plurality of SSBs are sequentially numbered in ascending order of SSB indexes of the plurality of SSBs from one, N is a number of the plurality of SSBs, and x is an integer greater than or equal to zero and less than a number of the at least one PDCCH monitoring occasion in the SI window divided by N; and monitoring at least one PDCCH monitoring occasion associated with at least one of the plurality of SSBs to acquire the SI message.
 2. The method of claim 1, wherein the number of the at least one PDCCH monitoring occasion in the SI window is greater than the number of the plurality of SSBs.
 3. The method of claim 1, further comprising: receiving, from the base station, information on the plurality of SSBs in a system information block (SIB) 1, wherein each of the plurality of SSBs is identified based on the information on the plurality of SSBs.
 4. The method of claim 1, further comprising: receiving, from the base station, configuration information on a search space for SI message reception, wherein the at least one PDCCH monitoring occasion is identified based on the configuration information.
 5. A terminal in a wireless communication system, comprising: a transceiver; and a controller coupled with the transceiver and configured to: control the transceiver to receive, from a base station, a plurality of synchronization signal blocks (SSBs), identify at least one physical downlink control channel (PDCCH) monitoring occasion associated with each of the plurality of SSBs in a system information (SI) window, wherein an (x*N+K)th PDCCH monitoring occasion of the at least one PDCCH monitoring occasion in the SI window is mapped to a Kth SSB of the plurality of SSBs, where the at least one PDCCH monitoring occasion in the SI window is sequentially numbered from one, the plurality of SSBs are sequentially numbered in ascending order of SSB indexes of the plurality of SSBs from one, N is a number of the plurality of SSBs, and x is an integer greater than or equal to zero and less than a number of the at least one PDCCH monitoring occasion in the SI window divided by N, and monitor at least one PDCCH monitoring occasion associated with at least one of the plurality of SSBs to acquire an SI message.
 6. The terminal of claim 5, wherein the number of the at least one PDCCH monitoring occasion in the SI window is greater than the number of the plurality of SSBs.
 7. The terminal of claim 5, wherein the controller is further configured to control the transceiver to receive, from the base station, information on the plurality of SSBs in a system information block (SIB) 1, and wherein each of the plurality of SSBs is identified based on the information on the plurality of SSBs.
 8. The terminal of claim 5, wherein the controller is further configured to control the transceiver to receive, from the base station, configuration information on a search space for SI message reception, and wherein the at least one PDCCH monitoring occasion is identified based on the configuration information.
 9. A method performed by a base station for transmitting a system information (SI) message, comprising: transmitting, to a terminal, a plurality of synchronization signal blocks (SSBs); and transmitting, to the terminal, the SI message in at least one physical downlink control channel (PDCCH) monitoring occasion in an SI window using a downlink beam corresponding to an SSB associated with the at least one PDCCH monitoring occasion among the plurality of SSBs, wherein an (x*N+K)th PDCCH monitoring occasion of the at least one PDCCH monitoring occasion in the SI window corresponds to a Kth SSB of the plurality of SSBs, where N is a number of the plurality of SSBs, x is an integer greater than or equal to zero and less than a number of the at least one PDCCH monitoring occasion in the SI window divided by N.
 10. The method of claim 9, further comprising: transmitting, to the terminal, information on the plurality of SSBs and configuration information on a search space for SI message reception in a system information block (SIB)
 1. 11. A base station in a wireless communication system, comprising: a transceiver; and a controller coupled with the transceiver and configured to: control the transceiver to transmit, to a terminal, a plurality of synchronization signal blocks (SSBs), and control the transceiver to transmit, to the terminal, a system information (SI) message in at least one physical downlink control channel (PDCCH) monitoring occasion in an SI window using a downlink beam corresponding to an SSB associated with the at least one PDCCH monitoring occasion among the plurality of SSBs, wherein an (x*N+K)th PDCCH monitoring occasion of the at least one PDCCH monitoring occasion in the SI window corresponds to a Kth SSB of the plurality of SSBs, where N is a number of the plurality of SSBs, x is an integer greater than or equal to zero and less than a number of the at least one PDCCH monitoring occasion in the SI window divided by N.
 12. The base station of claim 11, wherein the controller is further configured to control the transceiver to transmit, to the terminal, information on the plurality of SSBs and configuration information on a search space for SI message reception in a system information block (SIB)
 1. 